This invention relates generally to an improved apparatus for use in electrolytically removing material from a workpiece and more specifically to an apparatus utilized in associated with electrodes which are movable through working strokes during the electrolytic removal of material from a workpiece.
A known apparatus having one or more electrodes to electrolytically remove material from a workpiece is disclosed in U.S. Pat. No. 3,287,245. The apparatus disclosed in U.S. Pat. No. 3,287,245 contemplates that an electrode will be moved from a retracted position to a beginning of working stroke position at a relatively high speed by a screw and nut drive arrangement. When the electrode has been moved at a high speed to a position closely adjacent to the workpiece, the speed of movement of the electrode is reduced and the electrode is moved through a working stroke at a constant speed. A plurality of different devices are provided to sense when the electrode has been moved through a high speed approach stroke and is about to begin a work stroke.
Another apparatus for moving an electrode at a relatively high speed to a beginning of work stroke position and for thereafter moving the electrode at a constant speed is disclosed in U.S. Pat. No. 3,275,543. Other machines having movable electrodes are disclosed in U.S. Pat. Nos. 3,372,099; 3,459,645; 3,466,235; 3,506,559; 3,547,797; 3,746,632 and 3,753,890. Various drive arrangements associated with machines other than machines for electrolytically removing material from a workpiece are disclosed in U.S. Pat. Nos. 1,907,208; 2,163,959 and 3,192,718.
It has been previously suggested to utilize optical or photoelectric sensors in association with an apparatus to adjust the position of the anode of an electrolytic cell in a manner disclosed in U.S. Pat. No. 3,902,983. It should be noted that the apparatus disclosed in U.S. Pat. No. 3,902,983 does not utilize the photoelectric device to detect the position of an electrode but merely detects when a voltage output of a cell is either at a high limit or a low limit. In addition, photoelectric devices have previously been utilized to determine when a weight connected with an electrode is in a predetermined position during the process of making the electrode (see U.S. Pat. No. 3,384,567). However, prior art machines for effecting electrolytic removal of material from a workpiece have not utilized photoelectric sensors to detect when an electrode is in a predetermined position during a working stroke.